Inactivation of MarR gene homologs increases susceptibility to antimicrobials in Bacteroides fragilis
| Autor: | Felipe Lopes Teixeira, Deborah Nascimento dos Santos Silva, Leandro Araujo Lobo, Juliana Soares de Sá Almeida, Renata F. Boente, Clara Maria Guimarães Silva, Regina Maria Cavalcanti Pilotto Domingues, Scarlathe Bezerra da Costa |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
030106 microbiology Mutant lcsh:QR1-502 Virulence Microbial Sensitivity Tests Microbiology lcsh:Microbiology Bacteroides fragilis 03 medical and health sciences Plasmid Antibiotic resistance Bacterial Proteins Humans Gene Silencing Genetics biology Biofilm Gene Expression Regulation Bacterial biology.organism_classification Bacteroides Infections Oxidative stress resistance Anti-Bacterial Agents Multiple drug resistance Repressor Proteins Multi-drug resistance Anaerobic bacteria 030104 developmental biology Research Paper |
| Zdroj: | Brazilian Journal of Microbiology, Volume: 49, Issue: 1, Pages: 200-206, Published: MAR 2018 Brazilian Journal of Microbiology v.49 n.1 2018 Brazilian Journal of Microbiology Sociedade Brasileira de Microbiologia (SBM) instacron:SBM Brazilian Journal of Microbiology, Vol 49, Iss 1, Pp 200-206 |
| Popis: | Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs. Regulators like MarR, that control expression of the locus mar, also regulate resistance to organic solvents, disinfectants and oxygen reactive species are important players in these events. Strains derived from the parental strain 638R, with mutations in the genes hereby known as marRI (BF638R_3159) and marRII (BF638R_3706) were constructed by gene disruption using a suicide plasmid. Phenotypic response of the mutant strains to hydrogen peroxide, cell survival assay against exposure to oxygen, biofilm formation, resistance to bile salts and resistance to antibiotics was evaluated. The results showed that the mutant strains exhibit statistically significant differences in their response to oxygen stress, but no changes were observed in survival when exposed to bile salts. Biofilm formation was not affected by either gene disruption. Both mutant strains however, became more sensitive to multiple antimicrobial drugs tested. This indicates that as observed in other bacterial species, MarR are an important resistance mechanism in B. fragilis. |
| Databáze: | OpenAIRE |
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